Apparatus for recording an image of the local distribution and the radiation intensity of radioactive materials deposited in a space



July 5, 1966 A. ZIEGLER 3 ,7 7

APPARATUS FOR RECORDING AN IMAGE OF THE LOCAL DISTRIBUTION AND THERADIATION INTENSITY OF RADIOACTIVE MATERIALS DEPOSITED IN A SPACE FiledSept. 10, 1963 2 Sheets-Sheet 1 Fig.1

July 5, 1966 A. ZIEGLER 3,259,747

APP '1' FOR ORDING AN IMAGE OF TH OCAL DISTRIBUTION A RAD ION INTENSI OFRADI TIVE MATERIALS DEPOSITE A SPACE Filed Sept. 10, 1963 2 Sheets-Sheet2 United States Patent Germany, a corporation of Germany Filed Sept. 10,1963, Ser. No. 308,030 Claims priority, application Germany, Sept. 21,1962,

9 Claims. (a. ass-6s My invention relates to a method and apparatus fordetermining the radioactivity of materials and more particularly, fordetermining the local distribution and radiation intensity ofradioactive materials deposited in a space.

Spaces in which radioactive materials are used or into which radioactivematerial can penetrate, for example walks and other spaces used bypersonnel to gain access in nuclear reactor installations for repair andmaintenance thereof, must be continuously inspected for radioactiveradiations. In such spaces, local contaminations are frequently producedprimarily because of the deposit of radioactive materials at locationsthat are not satisfactorily ventilated or that are incompletely rinsedwith fluids. Access to such spaces is consequently made difiicult and onmany occasions is generally impossible. When the locations from whichthe radioactive radiation emanates are known, however, the radioactivematerials deposited there can be removed or can be screened oif byconstructing a protective wall. The usual dosage measurement withcounter tubes, ionization chambers or films, provides no information asto where the radiation comes from (i.e. the location of the source ofthe radiation).

It is accordingly an object of my invention to provide a method andapparatus for determining the source location and the intensity ofradiation of radioactive material located in a space.

With the above and other related objects in view, and in accordance withmy invention, I provide a point by point recorded image of the radiationplaced into registry with 8. represented image of the space as seen fromthe same viewing angle. A photograph is used advantageously for theimage of the space and is taken from the same point from which the imageof the radiation is recorded. The distribution of radioactive materialcan then be directly read therefrom. A camera with a displaceableobjective is used for recording or radiographing the radiation image.The degree of photographic or radiographic density of the radiationimage is adjustable to the intensity and the intended exposure time bymeans of a suitable choice of objective stops. An integrating recordover a relatively long period is also possible.

The camera which is used for recording the radiation image in accordancewith my invention comprises a chamher that is screened from radioactiveradiation on all sides, for example with lead, is provided with areplaceable carrier coated with a radiation-sensitive film and is alsoprovided with a sphere acting as objective which is formed with a borehole running through its center and is rotatable about two axes that areperpendicular to one another. The sphere also consists of lead or anyother good radiation screening material. One of the axes about which thesphere is rotatable coincides with the center axis of the bore hole. Theother axis which is perpendicular thereto is defined by two trunnionsthat are arranged diametrically in a ring surrounding the sphere. Thecamera is thus in a position to photograph every point within an angleof 90 in this space.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

The invention, both as to its construction and method of operation,together with additional objects and advantages thereof, will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings, in which:

FIG. 1 is a sectional view of the camera for photographing radiationconstructed in accordance with my invention;

FIG. 2 is a front elevational View of FIG. 1 partly in section as viewedalong the line lIl1 in FIG. 1 in the direction of the arrows;

FIG. 3 is a fragmentary sectional view of FIG. 2 taken along the lineIII-III in the direction of the arrows; and

FIG. 4 is a perspective view partly in section of a camera embodying myinvention, having a drive mechanism which differs from the drivemechanism shown in FIG. 1.

Referring to the drawings and first particularly to FIGS. 1 and 2, thereis shown a camera which includes a hollow body 10 consisting of materialthat screens radioactive radiation, such as lead for example, andprovided with a hollow space 11 defined by a removable rear wall 12 anda sphere 13. The surface of the hollow body wall 10 adjacent to thesphere 13 conforms to the sphere with slight play therebetween. There isprovided on the rear wall 12 a film holder for receiving a plate 14 orphotographic film which is coated with an emulsion that becomesblackened by radioactive radiation. The rear wall 12 and the sphere 13also consist of material, such as lead for example, which screens outradioactive radiation. The sphere is provided with a graduated bore holepassing through its center within which there is accommodated aninterchangeable insert 15 formed with a longitudinally extending bore.The sphere is also provided with two diametrically arranged pivot bossesor trunnions 17 which are rotatably mounted in a gimbal ring 16 whichconcentrically surrounds the sphere. The inner surface of the ring 16conforms to the sphere, and a toothed ring 13 in which a pinion 19meshes is arranged on the outer surface of the gimbal ring 16. The ring16 is mounted in the hielding body 10 with the aid of a slide bearing 20and, with the aid of another slide bearing 21, in a retaining ring orballoon catch 22 which is screwed into the shielding body 10. The ring16 carries another coaxial ring 23 which is also provided with a toothedring 24. The toothed ring 24 whose diameter is, for example, larger thanthat of the toothed ring 18, is driven by a pinion 25 which is securedtogether with the pinion 19 on a common shaft 26. The toothed rings 16and 24 consequently rotate at different speeds. Milled into the innerside of the ring 23 is a guiding groove 27 which is engaged by aprojection 29 of a slide 28 (FIG. 3). At the other end of the slide 28there is provided a pivot boss 30 which is inserted in a recess 31provided in the sphere 13. Due to the difference in the motion of the[rings 16 and 23, the slide 28 rotates the sphere 13 about the axisdetermined by the pivot bosses 17 so that the bore hole of the sphere ismoved slowly through an angle with respect to the longitudinal axis ofthe camera (i.e. about an axis at 17 perpendicular to the plane of thepaper as shown in FIG. 1) while the sphere simultaneously rotates aboutthe longitudinal axis of the camera (i.e. about the dot-dash line shownin FIG. 1). Due to the suitable profiling of the corridor, the rayswhich penetrate through the bore hole of the sphere draw an image of thespace in spiral lines on the radiation-sensitive emulsion of the plateor film 14, so that the entire picture area is simultaneously irradiatedor illuminated. The extent to which the emulsion is blackened can beadjusted to the intensity and exposure period provided for by means ofthe insert 15. To this end, in accordance with the need, inserts withlarger or smaller bore holes can be used, thereby producing the effectof a diaphragm. In order to prevent the penetration of radioactiveparticles into the interior of the camera, the front opening of thecamera housing can be covered by a radiation-permeable metal sheet, forexample of aluminum.

Another embodiment of a movable objective system is shown schematicallyin a perspective view in FIG. 4. The sphere 13 with an interchangeableobjective insert 15 is mounted by diametrically arranged trunnions 34 ina ring 33, the inner surface of which conforms to the sphere surface andthe outer casing of which is interrupted stepwise so that thepenetration of radiation is prevented. The ring 33 is rotatably mountedin the shielding camera body or housing and is provided on one side, forexample, with a toothed ring 37 in which a pinion 38 se cured to adriven shaft 39 meshes. One of the pivot trunnions 34 extends throughthe ring 33 and carries a pinion 35 which rotates through a groove 40 inthe housing 10 as the ring 33 rotates. The pinion accordingly mesheswith a toothed ring 36 mounted on one of the two side walls of thegroove. The sphere 13 rotates therefore with this construction about twoaxes that are perpendicular to each other. Since the rotational velocityof the sphere about the axis determined by the trunnions 34 is quitelarge compared to the rotational velocity of the ring 33, the sketch ofthe radiation is drawn in parallel, inclined or slightly crooked lineson the radiationsensitive emulsion.

While the invention has been illustrated and described as embodied in anapparatus for determining the local distribution and radiation intensityof radioactive material deposited in a space and the method of eifectingthe same, it is not intended to be limited to [the details shown, sincevarious modification and structural changes may be made withoutdeparting from the spirit of the present invention and within the scopeand range of equivalents of the following claims.

I claim:

1. An apparatus for determining the local distribution and radiationintensity of radioactive materials deposited in a space, comprising achamber shielded on all sides against radioactive radiation, replaceablecarrier means including an illustration of the space taken from aspecific viewing angle, said illustration being coated with aradiationsensitive film and being mounted in a specific plane in saidchamber, and a sphere partly defining said chamber and spaced from saidradiation-sensitive film, said sphere being formed with a central borecommunicating between said chamber and the exterior thereof and beingrotatable about a pair of mutually perpendicular axes, one of said axesbeing located transverse to said specific plane and the other of saidaxes being located substantially parallel thereto, said one axiscoinciding at a position of said sphere with the axis of said bore, saidsphere being provided with a pair of opposed trunnions aligned on theother of said axes, and mechanism for rotating said sphere, saidmechanism comprising first rotatable means surrounding said sphere andhaving an axis of rotation coinciding with said one axis, drive meansfor rotating said first rotatable means about said axis of rotation,said trunnions being diametrically mounted in said first rotatablemeans, and second rotatable means connected between said first rotatablemeans and said sphere for rotating said sphere about said other axis assaid first rotatable means is rotated about said axis of rotation bysaid drive means, so that an area of the space wherein radioactivematerials are deposited at the exterior of said chamber and acorresponding area of said radiation-sensitive film are simultaneouslyscannable at said specific viewing angle through said bore, whereby saidsphere acts as a camera objective focussing radiation in the exteriorarea through said bore onto said radiation-sensitive film for forming arecorded image of the radiation superimposed on said illustration.

2. An apparatus according to claim 1 wherein the i1lus tration of saidcarrier means comprises a photograph of the space in which theradioactive materials are deposited taken along the same viewing angleas the viewing angle along which the recorded image of the radiation onthe radiation-sensitive film is taken.

3. Apparatus according to claim 1, wherein said sphere includes atubular insert interchangeably secured in a diametrical bore hole ofsaid sphere, said central bore of said sphere extending longitudinallythrough said insert and being of selected diameter and shape.

4. An apparatus for determining the local distribution and radiationintensity of radioactive materials deposited in a space, comprising achamber shielded on all sides against radioactive radiation, replaceablecarrier means including an illustration of the space taken from aspecific viewing angle, said illustration being coated with arad-iation-sensitive film and being mounted in a specific plane in saidchamber, and a sphere partly defining said chamber and spaced from saidradiation'sensitive film, said sphere being formed with a central borecommunicating between said chamber and the exterior thereof and beingrotatable about a pair of mutually perpendicular axes, one of said axesbeing located transverse to and the other substantially parallel to saidspecific plane, said one axis coinciding at a position of said spherewith the axis of said bore, said sphere being provided with a pair ofopposed trunnions aligned on the other of said axes, and mechanism forrotating said sphere, said mechanism comprising a ring surrounding saidsphere and having an axis of rotation coinciding with said one axis,drive means for rotating said ring about said axis of rotation, saidtrunnions being diametrically mounted in said ring, and rotatable meansconnected between said ring and said sphere and adapted to rotate saidsphere about said other axis as said ring is rotated about said axis ofrotation by said drive means so that an area of the space whereinradioactive materials are deposited at the exterior of said chamber anda corresponding area of said radiation-sensitive film are simultaneouslyscannable at said specific viewing angle through said bore, whereby saidsphere acts as a camera objective focussing radiation in the exteriorarea through said bore onto said radiation-sensitive film for forming arecorded image of the radiation superimposed on said illustration.

5. An apparatus for determining the local distribution and radiationintensity of radioactive materials deposited in a space, comprising achamber shielded on all sides against radioactive radiation, replaceablecarrier means including an illustration of the space taken from aspecific viewing angle, said illustration being coated with a radiation-sensitive film and being mounted in a specific plane in saidchamber, and a sphere partly defining said chamber and spaced from saidradiation-sensitive film, said sphere being formed with a central borecommunicating between said chamber and the exterior thereof and beingrotatable about a pair of mutually perpendicular axes, one of said axesbeing located transverse to and the other substantially parallel to saidspecific plane, said one axis coinciding at a position of said spherewith the axis of said bore, said sphere being also provided with a pairof opposed trunnions aligned on the other of said axes, and

mechanism for rotating said sphere, said mechanism comprising a firstring surrounding said sphere and having an axis of rotation coincidingwith said one axis, drive means for rotating said first ring about saidaxis of rotation, said trunnions being diametrically mounted in saidfirst ring, a second ring coaxially mounted on said first ring androtatably driven by said drive means about said axis of rotation at arotary speed different from that of said first ring, a slide memberhaving a projection slidably engageable in a groove formed on the innersurface of said second ring and pivotably mounted on said sphere so asto rotate said sphere about said other axis as said rings are rotatedabout said axis of rotation by said driving means, so that an area ofthe space wherein radioactive materials are deposited at the exterior ofsaid chamber and a corresponding area of said radiation sensitive filmare simultaneously scannable at said specific viewing angle throughopposite ends of said bore, whereby said sphere acts as a cameraobjective focussing radiation in the exterior area through said boreonto said radiation-sensitive film for forming a recorded image of theradiation superimposed on said illustration.

6. An apparatus according to claim 5 wherein one of said pair of ringsis mounted circumferentially on the other of said rings and said ringsare rotatable relative to each other about said one axis.

7. An apparatus for determining the local distribution and radiationintensity of radioactive materials deposited in a space, comprising achamber shielded on all sides against radioactive radiation, replaceablecarrier means including an illustration of the space taken from aspecific viewing angle, said illustration being coated with a radiationsensitive film and being mounted in a specific plane in said chamber, asphere partly defining said chamber and spaced from saidradiation-sensitive film, said sphere being formed Wit-h a central borecommunicating between said chamber and the exterior thereof and beingrotatable about a pair of mutually perpendicular axes, one of said axesbeing located transverse to and the other substantially parallel to saidspecific plane, said one axis coinciding at a position of said spherewith the axis of said bore, said sphere being also provided with a pairof opposed trunnions aligned on the other of said axes, and mechanismfor rotating said sphere, said mechanism comprising a pair of relativelyrotatable coaxial rings surrounding said sphere and having an axis ofrotation coinciding with said one axis, said trunnions beingdiametrically and pivotably mounted on one of said rings, said ringsbeing of different diameter and provided with teeth along theirperiphery, drive means comprising a pair of coaxial pinions secured to acommon shaft, said pinions meshing respectively with the teeth of saidrings for rotating said rings, and a slide member having a projectionslidably engageable in a groove formed on the inner surface of the otherof said rings and pivotably mounted on said sphere so .as to rotate saidsphere about said other axis as said rings are rotated about said axisof rotation by.

said pinions, so that an area of the space wherein radioactivem-aterials are deposited at the exterior of said chamber and acorresponding area of said radiation-sensitive film are simultaneouslyscannable at said specific viewing angle through opposite ends of saidbore in a substantially spiral trace, whereby said sphere acts as acamera objective focussing radiation in the exterior area through saidbore onto said radiation-sensitive film for forming a recorded image ofthe radiation superimposed on said illustration.

8. An apparatus for determining the local distribution and radiationintensity of radioactive materials deposited in a space, comprising achamber shielded on all sides against radioactive radiation, replaceablecarrier means including an illustration of the space taken from aspecific viewing angle, said illustration being coated with aradiation-sensitive film and being mounted in a specific plane in saidchamber, a sphere partly defining said chamber and spaced from saidradiation-sensitive film, said sphere being formed with a central borecommunicating between said chamber and the exterior thereof and beingrotatable about a pair of mutually perpendicular axes, one of said axesbeing located transverse to and the other substantially parallel to saidspecific plane, said one axis coinciding at a position of said spherewith the axis of said bore, said sphere being also provided with a pairof opposed trunnions aligned on the other of said axes, and mechanismfor rotating said sphere, said mechanism comprising a pair of relativelyrotatable coaxial rings of different diameter surrounding said sphereand provided with teeth along their outer periphery, said rings havingan axis of rotation coinciding with said one axis, said trunnions beingdiametrically and pivotably mounted on one of said rings, drive meanscomprising a pair of coaxial pinions of different diameter secured to acommon shaft, said pinions of smaller and larger diameters meshingrespectively with the teeth of said rings of larger and smallerdiameters for rotating said rings at respectively greater and lesserspeeds, and a slide member having a projection at one end thereofslidably engageable in an arcuate groove formed on the inner surface ofthe other of said rings and :having a pivot at the other end thereofreceived in a recess in said sphere so as to rotate said sphere aboutsaid other axis as said rings are rotated about said axis of rotation bysaid pinions, so that an area of the space wherein radioactive materialsare deposited at the exterior of said chamber and a corresponding areaof said radiation-sensitive film are simultaneously scannable at saidspecific viewing angle through opposite ends of said bore in asubstantially spiral trace, whereby said sphere acts as a cameraobjective focussing radiation in the exterior area through said boreonto said radiation-sensitive film for forming a recorded image of theradiation superimposed on said illustration.

9. An apparatus for determining the local distribution and radiationintensity of radioactive materials deposited in a space, comprising achamber shielded on all sides against radioactive radiation, replaceablecarrier means including an illustration of the space taken from aspecific viewing angle, said illustration being coated with aradiation-sensitive film and being mounted in a specific plane in saidchamber, a sphere partly defining said chamber and spaced trom saidradiation-sensitive film, said sphere being formed with a central borecommunicating between said chamber and the exterior thereof and beingrotatable about a pair of mutually perpendicular axes, one of said axesbeing located transverse to and the other substantially parallel to saidspecific plane, said one axis coinciding at a position of said spherewith the axis of said bore, said sphere being also provided with a pairof opposed trunnions aligned on the other of said axes, a ringsurrounding said sphere and having an axis of rotation coinciding withsaid one axis, means for rotating said ring about said axis of rotation,said trunnions being diametrically mounted in said rotatable ring, oneof said trunnions extending through said ring and carrying a pinion atthe free end thereof, said chamber having a cylindrical wall surroundingand journalling said ring, said cylindrical wall being formed with aninner annular groove adjacent the periphery of said ring, said groovehaving a lateral annular surface provided with teeth, said pinion beingreceived in said groove in meshing engagement with the teeth of saidlateral annular surface thereof for rotating said sphere about saidother axis as said ring is rotated about said axis of rotation by saidrotating means so that an area of the space wherein radioactivematerials are deposited at the exterior of said chamber and acorresponding area of said radiation-sensitive film are simultaneouslyscannable at said specific viewing angle through opposite ends of saidbore, whereby said sphere acts as a camera objective focussing radiationin the exterior area through said bore onto said radiation-sensitivefilm for forming a recorded image of the radiation superimposed on saidillustration.

References Cited by the Examiner UNITED STATES PATENTS 2,285,768 6/ 1942Drucker 50 X 2,335,700 11/ 1943 Rogers 9550 X 2,396,069 3/ 1946 Zapp2506S 2,400,516 5/1946 Kieffer 250-61.5 2,684,446 7/ 1954 Paatero 250-652,895,049 7/ 1959 Astheimer et :al. 250-65 RALPH G. NILSON, PrimaryExaminer.

W. F. LINDQUIST, Assistant Examiner.

1. AN APPARATUS FOR DETERMINING THE LOCAL DISTRIBUTION AND RADIATIONINTENSITY OF RADIOACTIVE MATERIALS DEPOSITED IN A SPACE, COMPRISING ACHAMBER SHIELDED ON ALL SIDES AGAINST RADIOACTIVE RADIATION, REPLACEABLECARRIER MEANS INCLUDING AN ILLUSTRATION OF THE SPACE TAKEN FROM ASPECIFIC VIEWING ANGLE, SAID ILLUSTRATION BEING COATED WITH ARADITION-SENSITIVE FILM AND BEING MOUNTED IN A SPECIFIC PLANE IN SAIDCHAMBER, AND A SPHERE PARTLY DEFINING SAID CHAMBER AND SPACED FROM SAIDRADIATION-SENSITIVE FILM, SAID SPHERE BEING FORMED WITH A CENTRAL BORECOMMUNICATING BETWEEN SAID CHAMBER AND THE EXTERIOR THEREOF AND BEINGROTATABLE ABOUT A PAIR OF MUTUALLY PERPENDICULAR AXES, ONE OF SAID AXESBEING LOCATED TRANSVERSE TO SAID SPECIFIC PLANE AND THE OTHER OF SAIDAXES BEING LOCATED SUBSTANTIALLY PARALLEL THERETO, SAID ONE AXISCOINCIDING AT A POSITION OF SAID SPHERE WITH THE AXIS OF SAID BORE, SAIDSPHERE BEING PROVIDED WITH A PAIR OF OPPOSED TRUNNIONS ALIGNED ON THEOTHER OF SAID AXES, AND MECHANISM FOR ROTATING SAID SPHERE, SAIDMECHANISM COMPRISING FIRST ROTATABLE MEANS SURROUNDING SAID SPHERE ANDHAVING AN AXIS OF ROTATION COINCIDING WITH SAID ONE AXIS, DRIVE MEANSFOR ROTATING SAID FIRST ROTATABLE MEANS ABOUT SAID AXIS OF ROTATION,SAID TRUNNIONS BEING DIAMETRICALLY MOUNTED IN SAID FIRST ROTATABLEMEANS, AND SECONE ROTATABLE MEANS CONNECTED BETWEEN SAID FIRST ROTATABLEMEANS AND SAID SPHERE FOR ROTATING SAID SPHERE ABOUT SAID OTHER AXIS ASSAID FIRST ROTATABLE MEANS IS ROTATED ABOUT SAID AXIS OF ROTATION BYSAID DRIVE MEANS, SO THAT AN AREA OF THE SPACE WHEREIN RADIOACTIVEMATERIALS ARE DEPOSITED AT THE EXTERIOR OF SAID CHAMBER AND ACORRESPONDING AREA OF SAID RADIATION-SENSITIVE FILM ARE SIMULTANEOUSLYSCANNABLE AT SAID SPECIFIC VIEWING ANGLE THROUGH SAID BORE, WHEREBY SAIDSPHERE ACTS AS A CAMERA OBJECTIVE FOCUSSING RADIATION IN THE EXTERIORAREA THROUGH SAID BORE ONTO SAID RADIATION-SENSITIVE FILM FOR FORMING ARECORDED IMAGE OF THE RADIATION SUPERIMPOSED ON SAID ILLUSTRATION.